Key points are not available for this paper at this time.
Catostomid fishes appear to have 2n(-->4n?) approximately 100 chromosomes. The Cyprinidae, from which catostomids probably diverged before the Eocene, usually have 2n = 48 or 50 chromosomes. Preliminary cytophotometric measurements indicate an approximate doubling of DNA content of cells among catostomids.
Uyeno et al. (Fri,) studied this question.